Pain, which is a common disease in clinic, which is divided into three types: physical pain, inflammatory pain and neuralgia. At present, the analgesic drugs used in clinic mainly includes two categories, namely non-steroidal anti-inflammatory drugs (NSAIDs) and opiates.
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat acute and chronic pain. They also can be used as the adjuvant reagents of the opiates. Commonly used non-steroidal anti-inflammatory drugs include: Aspirin, Ibuprofen, Indomethacin, Diclofenac, Ketorolac and Acetaminophen. Unfortunately, NSAIDs show some side-effects, such as stimulation to gastrointestinal tract and ulcers.
In clinic, if non-steroidal anti-inflammatory drugs can't relieve the pain totally, they would be used in combination with opiates. Commonly used opioids such as Morphine and Codeine can treat moderate to severe pains. Although opioids are potent analgesic effect, their clinical applications are strictly restricted because of their severe side effects, such as addiction, tolerance and respiratory depression.
Recently, the inventors disclosed a quaternary ammonium salt compounds of piperazines represented by Formula I˜IV in Chinese patent application CN 01142111.8, which are novel compounds with potent analgesic effect and had no NSAIDs- or opiate-like side-effects. Their structures are showed below:

Base on the patent application mentioned above, in the present invention, we further discovered a series of novel quaternary ammonium salt compounds of piperazines with spirocyclo-structure, which has good analgesia function and no addiction.